Neuren Pharmaceuticals Reports Record DAYBUE Royalties as Rett Syndrome Therapy Sales Exceed $100 Million Quarterly Milestone
Key Insights
Neuren Pharmaceuticals achieved record quarterly royalties of A$16.4 million from DAYBUE (trofinetide), driven by Acadia Pharmaceuticals' US$101.1 million in third-quarter sales for the Rett syndrome (search) therapy.
The number of patients receiving DAYBUE shipments surpassed 1,000 for the first time, with 74% of new prescriptions now written by community-based physicians rather than specialists.
Neuren's second drug candidate NNZ-2591 has initiated its first-ever Phase 3 trial for Phelan-McDermid syndrome (search), marking a significant milestone for this rare neurodevelopmental disorder with no approved treatments.
Neuren Pharmaceuticals has achieved a significant commercial milestone as quarterly sales of its Rett syndrome (search) therapy DAYBUE (trofinetide) exceeded US$100 million for the first time, generating record royalties for the Australian biotechnology company. The achievement underscores the growing market penetration of the first FDA-approved treatment for Rett syndrome and positions Neuren for continued growth across its neurodevelopmental disorder pipeline.
DAYBUE Achieves Commercial Breakthrough
Acadia Pharmaceuticals, Neuren's exclusive worldwide licensing partner, reported US$101.1 million in DAYBUE net sales for the September quarter, representing an 11% increase year-over-year and 5% growth from the previous quarter. This translated into A$16.4 million in third-quarter royalties for Neuren, up 24% year-over-year and 12% from the second quarter of 2025.
The milestone reflects expanding patient access, with the number of patients receiving DAYBUE shipments rising above 1,000 for the first time. Notably, 74% of new prescriptions are now written by community-based physicians rather than specialists in designated Rett syndrome (search) centers, indicating broader physician adoption beyond specialized treatment centers.
"We're delighted to see the continued growth in patient access and the strengthening of community-based prescribing," said Neuren CEO Jon Pilcher. "The increasing awareness and uptake of DAYBUE demonstrate both the clinical value of the therapy and the quality of Acadia's commercial execution."
Market Penetration and Growth Potential
Long-term treatment persistence remained steady above 50% after 12 months, while overall U.S. market penetration reached approximately 40%. Within community settings, penetration stood at roughly 27%, highlighting continued room for growth. The quarter also delivered the most significant increase in referrals since launch, supported by Acadia's expanded field force.
Acadia has narrowed its full-year guidance for DAYBUE to between US$385 million and US$400 million, implying full-year royalties for Neuren of A$63 to 66 million, assuming an exchange rate of 0.65. This represents substantial growth from the $56 million in royalties Neuren earned in 2024.
International Expansion Underway
Beyond the United States, DAYBUE's global reach continues to expand. Acadia expects a CHMP opinion on its European marketing application in the first quarter of 2026 and has initiated a Phase 3 trial in Japan. Named patient supply programs for DAYBUE are active in multiple regions, including Europe, Israel, the Middle East, and Latin America.
The drug is currently approved by the U.S. Food and Drug Administration and Health Canada for the treatment of Rett syndrome (search), with significant growth potential remaining as two-thirds of diagnosed U.S. patients have yet to commence treatment.
NNZ-2591 Pipeline Advances
Neuren's wholly owned second drug candidate, NNZ-2591, has reached a critical development milestone with the initiation of its first-ever Phase 3 trial for Phelan-McDermid syndrome (search) (PMS). The company reached an agreement with the U.S. FDA on the design and primary endpoints of the pivotal trial, marking the first Phase 3 study for PMS, a condition with no currently approved treatments.
The candidate has produced positive Phase 2 results in Phelan-McDermid, Pitt Hopkins, and Angelman syndromes, with all three programs receiving orphan drug designation in both the U.S. and European Union. NNZ-2591 also received FDA Fast Track designation for Pitt-Hopkins syndrome and secured a U.S. patent valid until 2040.
Expanding Pipeline and Financial Strength
Development has begun for Hypoxic Ischemic Encephalopathy (search), a leading cause of neonatal death and long-term disability, while SYNGAP1-related disorder (search) has been added to the pipeline following promising preclinical results. The incidence of SYNGAP1-related disorder is estimated at one in 16,000 individuals, with no approved therapies currently available.
Neuren's strong financial position supports this accelerated investment, with the company holding $300 million in cash and short-term investments at June 30, up from $222 million at the end of 2024. The company completed a $50 million share buyback at an average price of $12.27 per share, while nearly doubling its profit after tax to $15 million in the first half of 2025.
"With a strong cash position, growing royalty stream, and multiple late-stage programs underway, Neuren is uniquely positioned to advance treatments for rare and devastating neurological conditions that currently have no approved therapies," Pilcher said.